Systems and methods for orthopedic implants

ABSTRACT

A system and computer-implemented method for manufacturing an orthopedic implant involves segmenting features in an image of anatomy. Anatomic elements can be isolated. Spatial relationships between the isolated anatomic elements can be manipulated. Negative space between anatomic elements is mapped before and/or after manipulating the spatial relationships. At least a portion of the negative space can be filled with a virtual implant. The virtual implant can be used to design and manufacture a physical implant.

CROSS-REFERENCE TO RELATED APPLICATION

This application is a continuation of U.S. application Ser. No.16/569,494, filed Sep. 12, 2019, which claims priority to and thebenefit of U.S. Provisional Patent Application No. 62/730,336, filedSep. 12, 2018, which are hereby incorporated by reference in theirentireties.

FIELD OF THE INVENTION

The field of the invention generally relates to orthopedic implants,including spinal implants, and methods for designing and producing them.

BACKGROUND

Orthopedic implants are used to correct a variety of different maladies.Orthopedic surgery utilizing orthopedic implants may include one of anumber of specialties, including: spine surgery, hand surgery, shoulderand elbow surgery, total joint reconstruction (arthroplasty), skullreconstruction, pediatric orthopedics, foot and ankle surgery,musculoskeletal oncology, surgical sports medicine, and orthopedictrauma. Spine surgery may encompass one or more of the cervical,thoracic, lumbar spine, or the sacrum, and may treat a deformity ordegeneration of the spine, or related back pain, leg pain, or other bodypain. Irregular spinal curvature may include scoliosis, lordosis, orkyphosis (hyper- or hypo-), and irregular spinal displacement mayinclude spondylolisthesis. Other spinal disorders includeosteoarthritis, lumbar degenerative disc disease or cervicaldegenerative disc disease, lumbar spinal stenosis or cervical spinalstenosis.

Spinal fusion surgery may be performed to set and hold purposefulchanges imparted on the spine during surgery. Spinal fusion proceduresinclude PLIF (posterior lumbar interbody fusion), ALIF (anterior lumbarinterbody fusion), TLIF (transverse or transforaminal lumbar interbodyfusion), or LLIF (lateral lumbar interbody fusion), including DLIF(direct lateral lumbar interbody fusion) or XLIF (extreme lateral lumbarinterbody fusion).

The goal of interbody fusion is to grow bone between vertebra in orderto seize the spatial relationships in a position that provides enoughroom for neural elements, including exiting nerve roots. An interbodyimplant device (or interbody implant, interbody cage, or fusion cage, orspine cage) is a prosthesis used in spinal fusion procedures to maintainrelative position of vertebra and establish appropriate foraminal heightand decompression of exiting nerves. Each patient may have individual orunique disease characteristics, but most implant solutions includeimplants (e.g. interbody implants) having standard sizes or shapes(stock implants).

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 shows a variety of traditional interbody implants.

FIG. 2 shows a representation of a spine with a pathological deformitysuch as adult degenerative scoliosis.

FIG. 3 shows a representation of a typical surgical implant kitcontaining stock implants delivered to spinal surgery.

FIG. 4 shows a representation of a typical stock implant includingseveral views.

FIG. 5 shows a representation of a spine with a pathological deformitythat has been surgically corrected with traditional stock interbodies.

FIG. 6 shows isolated lumbar vertebrae and coordinate systems to guideadjustment of relative positions between vertebrae.

FIG. 7 shows a representation of a patient specific-implant andpackaging as delivered to spinal surgery.

FIG. 8 shows a representation of a spine with a pathological deformitythat has been surgically corrected with patient-specific interbodies.

FIG. 9 shows a representation of a surgical planning user interface.

FIG. 10 shows a representation of a surgical planning user interfacewith tools to enable relative adjustments of vertebrae positioning.

FIG. 11 shows a representation of a lumbar spine with the negative spacebetween the vertebrae highlighted.

FIG. 12 shows the details of an individual negative space resulting fromthe adjustment of the relative positions of the vertebrae.

FIG. 13 shows the details of an individual patient-specific implantdesigned to fill at least a portion of the negative space includingbi-planar angulation and endplate topography.

FIG. 14 shows the contents of one embodiment of a patient-specificsurgical implant kit, including implants and implant inserter.

FIG. 15 shows three lumbar vertebrae and highlighted vertebralendplates.

FIG. 16 shows top and side views of a vertebra.

FIG. 17 illustrates a system for providing assistance for manufacturinga patient specific-implant.

FIG. 18 is a flow diagram illustrating a method for manufacturing animplant in accordance with an embodiment.

FIG. 19 is a flow diagram illustrating a method for manufacturing animplant in accordance with another embodiment.

DETAILED DESCRIPTION

A patient-specific medical device and an efficient method of producing apatient-specific interbody implant is described in the embodimentsherein. Devices according to embodiments described herein may includeinterbody implants, fusion cages, or other implants. The interbodyimplants are typically intended to be placed in the space (created bysurgical intervention) between two vertebrae. In fusion surgeries, theintervertebral disc may be surgically removed prior to the placement ofthe interbody implant. The lower (inferior) side of an interbody implantis intended to abut at least a portion of an upper (superior) side of afirst vertebrae and the superior endplate of the interbody implant isintended to abut at least a portion of an inferior endplate of a secondvertebrae.

Insufficient contact and load transfer between the vertebrae (anatomy)and the interbody implant (device) can produce inadequate fixation.Inadequate fixation can allow the cage to move relative to thevertebrae. Furthermore, insufficient contact area or fixation betweenthe interbody implant and the vertebrae can result in micro- and/ormacro-motions that can reduce the opportunity for bone growth and fusionto occur. If enough motion occurs, expulsion of the interbody implant orsubsidence of the interbody implant into the adjacent vertebrae canresult.

Traditional implants are selected intraoperatively from a surgical kitcontaining likely sizes and shapes depending on the surgical approachand patient anatomy. Selection of implant size is performed by thesurgeon during the surgery while the patient's spine is exposed. Often,minimal consideration is paid to implant size prior to the surgery. Themethod for selecting implant size is “trialing,” whereby the surgeonuses a series of incrementally sized implant proxies to determine theappropriate implant size and shape. This method presents severalopportunities for improvements.

Significant intra-operative attention is paid to the posterior heightand sagittal angle of the interbody implants; however, minimal attentionis paid to the lateral heights and coronal angle of the interbodyimplants. Even with the attention paid to the sagittal height, theimplants available in surgery only come in stock sizes that are unlikelyto provide optimal solutions for the particular patient or particularinterbody space. Additionally, traditional stock implants do not provideany options for variable coronal angles. By selecting stock implantsintraoperatively from a fixed assortment of implant sizes, the surgeonis unable to provide to the patient an optimal solution for correctionof the particular spinal deformity or pathological malalignment causingpatient pain.

Furthermore, intraoperative selection of stock implants requiresshipment and delivery of sufficient implants to cover the wide varietyof patients and their unique interbody spaces. The shipping,sterilization, processing, and delivery of enough implants to surgerycan be characterized as logistically burdensome and expensive. It is notuncommon for more than fifty implants to be delivered to a surgery thatrequires only one implant.

In one typical fusion procedure, posterior fixation devices (pediclescrews, spinal rods) are used to stabilize the spine. Additionally,anterior interbody implants provide spacing and decompression of neuralelements and a location for interbody fusion (bone growth between twovertebra).

Improper or sub-optimal sizing of interbody implants can result inimplant failures. If the interbody space is not sufficiently filled,posterior implants (including rods and plates) are required to carrymore dynamic loads prior to fusion. The typical failure mode of spinalrods include fracture due to dynamic loads; the increased magnitude ofthe movement due to an undersized interbody implant only exacerbates thecondition, leading to more implant failures.

Patient-specific interbody implants can be designed for optimal fit inthe negative space created by removal of the disc and adjustment of therelative position of vertebrae. Surgical planning software can be usedto adjust the relative positions of vertebrae and define the negativespace between the vertebrae. Modifying the spatial relationship betweenadjacent vertebrae within a virtual design space can provide adefinition of the 3D negative space into which an interbody can bedelivered. Software can further be used to compare the originalpathology to the corrected positions of the vertebrae. The optimal sizeand shape of patient-specific implants can prevent or reduce instancesof dynamic failure of posterior implants.

Presently, intraoperative imaging often requires radiation. Exposure toradiation should be reduced as low as reasonably possible. Surgeriesusing stock interbody implants require trialing to inform the selectionof the stock implant. Patient-specific implants do not require trialing,as the size and shape of the implant has been determined prior to thesurgery using preoperative imaging and planning software.

The imaging tools available to the surgeon during surgery typically onlyinclude mobile radiography (bedside x-ray, c-arm, o-arm). The use ofmobile radiography exposes surgeons, staff, and patients tointraoperative radiation. The operating room environment does notprovide the same radiation shielding capabilities that a standarddedicated radiology room provides (leaded walls, leaded glass, etc.).Because of the desire to reconcile radiographic images with visible (andinvisible) anatomy, avoid sensitive anatomy, and understand relativeanatomical positions, surgeons are often in close proximity to or withinthe field of radiation during intraoperative imaging. It is advantageousto reduce or eliminate radiation exposure to the participants ofsurgery.

One method of designing patient-specific interbody implants includescapturing important anatomical geometry and relative positioning usingcomputed tomography (CT) or another imaging modality (MRI, simultaneousbi-planar radiography, etc.). The image data can be reconstructed intovolumetric data containing voxels that are representative of anatomy.Following the scan, the collected data can be ported to a workstationwith software to enable segmentation of relevant anatomy. A processcalled segmentation separates voxels representing bony anatomy from theother anatomy. Isolation of individual bony structures enables a user toappreciate each bony structure independently. Furthermore, followingisolation, the relationships between individual vertebrae (distances,angles, constraints, etc.) can be manipulated. Together with a surgeon,an engineer can manipulate the vertebrae thereby changing the spacingbetween the virtual anatomical structures. Manipulations can includetranslations along an axis or curve, rotation about an axis or centroid,or rotation about the center of mass, among other movements.Consideration is to be paid to the virtual manipulations to ensure theyare representative of anatomical constraints and manipulations that canbe achieved in a surgical setting. After the virtual manipulations ofselect vertebrae, the newly created negative space between the vertebraecan be mapped and characterized using design software. One way ofmapping the negative 3D space is to (1) select a bounding anatomicalfeature, such as a vertebral endplate, (2) create a best-fit planethrough the surface, (3) define a perimeter of the anatomical feature,and (4) extrude a volume defined by the perimeter and perpendicular tothe best-fit plane to the interface of another anatomical feature.

The newly created negative space between virtual vertebrae can be usedto determine geometric parameters (dimensions, angles, heights,surfaces, topographies, footprints, etc.) and external envelope foroptimal interbody implants.

After the external envelope for the patient-specific interbody (PSIB)implant has been determined, internal features, including lattice,struts, and apertures, can be designed. The internal features willdetermine the strength and bone incorporation qualities. Internalfeatures can be engineered to provide favorable conditions forosteo-integration, bony on-growth, bony in-growth, and bonythrough-growth. Internal features can also be designed to resist orallow deformation, resulting in an optimal structural stiffness orcompliance according to the physiological demands. In some patients,reducing the strength (stiffness) of the implant may create lessinstances of implant subsidence into the neighboring bones. In otherpatients, a stronger or stiffer implant may be designed to handle largeranticipated anatomical loads.

In some embodiments, a system and computer-implemented method formanufacturing an orthopedic implant involves segmenting features in animage of anatomy. The features can be anatomy of interest, such as bone,organs, etc. Anatomic elements (e.g., vertebrae, vertebral disks, etc.)can be isolated. Spatial relationships between the isolated anatomicelements can be manipulated. Before and/or after manipulating thespatial relationships, a negative space between anatomic elements can bemapped. At least a portion of the negative space can be filled with avirtual implant. The virtual implant can be used to select, design,and/or manufacture a patient-specific implant.

FIG. 1 shows a variety of typical interbody implants. Each of theimplants is surgically inserted using different anatomical approaches.ALIF (Anterior Lumbar Interbody Fusion) implant 10 is inserted from theanterior, through an incision in the abdomen. LLIF (Lateral LumbarInterbody Fusion) implant 12 is inserted from a lateral direction,through an incision in the side. PLIF (Posterior Lumbar InterbodyFusion) implant 14 is inserted from a posterior direction, through anincision in the back. TLIF (Transforaminal Lumbar Interbody Fusion)implant 16 is also inserted from a posterior direction, through anincision in the back. The PLIF device is typically inserted parallel tothe sagittal plane; whereas, the TLIF device is typically insertedthrough a neural foramen on a trajectory that is oblique to the sagittalplane.

FIG. 2 shows representations of a lumbar spine with adult degenerativescoliosis when viewed in the coronal plane 20 and sagittal plane 22.Sacrum 36 and lumbar vertebrae L5 38, L4 40, L3 42, L2 44, and L1 46 areshown in both coronal view 20 and sagittal view 22. Lumbar curvatures(coronal 24, sagittal 28) drawn through vertebrae centroids can be usedto characterize the deformity of the spine. Additionally, angles betweenvertebrae 32, 34 can also be used to characterize deformities. Idealcoronal curvature 26 and sagittal curvature 30 can be superimposed onthe Anterior-Posterior (AP) view 20 and Lateral (LAT) view 22.

FIG. 3 shows a representative stock interbody kit that is typicallydelivered to a single surgery. Top view 50 depicts a tray 54 containingthe matrix of interbody implants 52. Side view 51 show trays 54, 56 thatcontain implants and instruments to be used in surgery. Each kit iscontained within a steam sterilization case and trays 54, 56 that allowfor steam to penetrate the case and sterilize the contents. The numberof stock implants 52 contained within kit 50 can number overone-hundred. Instruments contained within kit 58 can be greater thantwenty.

FIG. 4 shows four views of a typical stock implant 60 (isometric 62, top64, front 66, side 68 views). Length 70, width 74, and height 72 arefundamental dimensions that define the overall envelope for stockimplants. Additionally, curvatures and radii 76, 78, 80 can furtherdescribe the implant geometry. Also depicted in stock implant 62 areapertures 82 that allow bone to grow from adjacent vertebral endplatesthrough the implant for fusion thereby completing fusion of adjacentvertebrae.

Each stock implant has several dimensions that vary for a specificinstance of an implant (length, width, height, curvatures, radii, etc.).Although these dimensions are infinitely variable, space, logistics andexpense limit inclusion of all instances within a surgical kit 50.

FIG. 5 shows the spine from FIG. 2 as treated with stock interbodyimplants. Implants 98 are positioned between the vertebrae duringsurgery to correct the spinal deformity. Due to the inability to provideall possible variations of stock implants to each surgery, correction ofa complex deformity is limited by the selection of implants from anexisting matrix of instances. Since each deformity is unique to thepatient, correction of the deformity using stock implants is necessarilysuboptimal.

As seen in FIG. 5 , suboptimal coronal and sagittal deformities canstill exist following surgery. The post-surgical coronal curvature 100deviates from the optimal coronal curvature 102. Additionally, thepost-surgical sagittal curvature 104 deviates from the optimal sagittalcurvature 106. Pathological curvatures and associated pain are theproximal reasons for undergoing surgery. If correction of the curvatureis not achieved, the patient remains at risk for continued pain. Onemethod of providing correction to pathological curvatures is to implantdevices that, when incorporated into the spinal column, re-align thespine to the appropriate curvature and relieve patient symptoms. AP 90and lateral view 92 depicts five interbody implants 98 that aim tocorrect the complex deformity, realign the spine, and/or relieve pain.If stock implants 98 are not properly sized and shaped, the curvature(and associated pain) may remain. Stock implants 98 cannot provide theoptimal amount of correction due to the limited nature of the offeringduring surgery.

FIG. 6 shows a patient-specific interbody contained within packaging. Inone embodiment implant 110 is inserted into one or many sterilizationenvelopes 112 that can be sterilized and opened during surgery. Label114 and other required identifying documents can be included with thepackaging or affixed to the sterilization envelopes 112 to identifyimplant 110. Identification can include patient identifier, surgeonidentifier, geometric parameters, spinal level for insertion, method ofinsertion, and date of surgery among other pieces of data.

FIG. 7 shows lumbar vertebrae, coordinate frames, and lumbar curvatures.Vertebrae 120 is shown in relation to other lumbar vertebrae. Therelationships between the vertebrae is often the cause of patient painand subsequent surgical intervention. Often adult degenerative scoliosisor another pathology cause the vertebrae to exert pressure on neuralelements, causing patient pain. Correction of positioning or re-aligningof the vertebrae can alleviate pain. The goal of the surgery is tore-align the vertebrae, remove pressure on the nerves, and fuse thevertebrae in place to provide lasting relief of pressure on the nerves.

Vertebrae 120 can be moved along coordinate systems 122 as defined bythe user. Manipulations can occur as (1) translations alongpredetermined or user-defined axis, (2) rotations about predetermined oruser-defined axis, (3) translations along predetermined oruser-generated curves, and (4) rotations about predetermined oruser-generated curves.

In one embodiment, coordinate systems 122 based on the centroid for eachvertebra is displayed in order to facilitate manipulation of eachvertebrae. In another embodiment, curvatures representing a best-fitcurve between centroids of adjacent vertebrae is created. Another curverepresenting the optimal curvature of vertebrae can be used tomanipulate vertebrae. A ‘snap’ feature can cause the vertebrae alignedin pathological conditions to automatically be positioned on a desiredcurve that represents optimal alignment for a patient.

In another embodiment, intersections between virtual solid models can becalculated. Where intersections or overlap of bony anatomy is detectedby the planning software, they can be resolved by an engineer,technician, or physician. Anatomical constraints, such as facet jointmobility, angles of facet articulating surfaces, and articulatingsurface size, must be considered during the alignment of virtualvertebrae. By manipulating the virtual models of vertebrae, the negativethree-dimensional space between the vertebrae can be appreciated. Aftercorrection of the virtual vertebrae has occurred, the negative spacethat results from the correction can be described. The description ofthe negative space can be used to inform the design of the interbodyimplant.

FIG. 15 shows three lumbar vertebra and highlighted vertebral endplates.FIG. 16 shows an individual vertebra as shown in axial 259 and lateral261 views. Vertebrae 260 have features including an anterior vertebralbody 262 containing endplates. Emphasis has been added to endplates inorder to appreciate the anatomical bounding features 264, 266 which canbe used to define the negative 3D volume between vertebral bodies. Facetjoint 268 restricts motion between vertebra. In order to appreciate the3D volume between the vertebrae, a best-fit plane 270 can be passedthrough the anatomical bounding features 264, 266. Vector 272,perpendicular to best-fit plane 270, can be constructed to providedirection for extruding a volume. Perimeter 274 can be drawn on plane270. Perimeter 274 can be extruded to opposing endplates 264, 266 orbounding anatomical features to define the negative 3D space. A portionof the negative 3D space 276 can be used to describe an implant 216.

In one embodiment, implant boundary 276 can be drawn on plane 270 torepresent an external shape of implant 216. Boundary 274 can beprojected from plane 270 to opposing anatomical endplates 264, 266 todefine the 3D shape of implant 216.

Implant 216 can be manufactured using one or more additive manufacturingor subtractive (traditional) manufacturing methods. Additivemanufacturing methods include, but are not limited to: three-dimensionalprinting, stereolithography (SLA), selective laser melting (SLM), powderbed printing (PP), selective laser sintering (SLS), selective heatsintering (SHM), fused deposition modeling (FDM), direct metal lasersintering (DMLS), laminated object manufacturing (LOM), thermoplasticprinting, direct material deposition (DMD), digital light processing(DLP), inkjet photo resin machining, and electron beam melting (EBM).Subtractive (traditional) manufacturing methods include, but are notlimited to: CNC machining, EDM (electrical discharge machining),grinding, laser cutting, water jet machining, and manual machining(milling, lathe/turning).

FIG. 8 shows AP 130 and lateral 132 images of a lumbar spine that hasbeen treated with patient-specific implants. The curves 138, 140 throughthe vertebrae of the lumbar spine 134 show that optimal alignment hasoccurred following placement of patient-specific interbodies 136. Themanipulation of the virtual vertebrae has aligned the vertebrae. In thisembodiment, the negative space between each vertebra can be optimallyfilled with virtual interbody implants. The parameters of the implantscan be used to manufacture each interbody implant. Each implant can bemanufactured using 3D printing. The implants can be packaged (includingidentifiers, labels, and instructions), sterilized, and delivered tosurgery.

FIG. 9 shows a graphical display of a surgical planning softwareapplication. In one embodiment, software planning application 150displays graphical and text information in several panes (152-166). Inpatient information pane 152, information about the patient, surgeon,and surgery can be displayed. Metric pane 154 can display parameters ofinterest to the user. Information like anatomical metric fields (pelvicincidence, lumbar lordosis, angle between vertebrae, distance betweenvertebrae, disc height, sagittal vertical axis, sacral slope, pelvictilt, Cobb angle, etc.) can be selected and displayed.

Three columns containing six panes 156, 158, 160, 162, 164, 166 can beused to easily compare pathologic anatomy and corrected anatomy. In oneembodiment, a column displaying information about the pathology withpanes 156, 158 can show a virtual model of the spine 156 above therelative metrics of that spine 158. The displayed spine can be rotated(zoomed, panned, etc.) to better display areas of interest. Anothercolumn containing panes 160, 162 can display images and information(anatomic metrics) about the corrected spine and patient-specificimplants in place.

The right column containing pane 164 can display images of pathologicaland corrected spine superimposed upon each other. The displayed spinescan be rotated (zoomed, panned, etc.) to better display areas ofinterest. Pane 166 can display some important specifications of thepatient-specific interbody implants, including posterior height,sagittal angle, coronal angle, anterior-posterior length, and width.

FIG. 10 shows a lumbar spine 171 and graphical representations of thecorrective maneuvers required to align the spine. AP 170 and lateral 172images can be shown in order to provide the clinician with a betterunderstanding of the correction that is required to reposition the spinein alignment. Arrows 174, 176 represent manipulations, maneuvers,rotations, or translations that will bring the spine back intoalignment.

FIG. 11 shows the corrected spine with the patient-specific interbodyimplants in place. Each interbody implant 182 is highlighted while thecorrected anatomy 180 is displayed as semi-transparent to allow forimproved appreciation of the design of each implant. The images can berotated, panned, or zoomed to provide better visibility to areas ofinterest.

FIG. 12 shows an individual vertebral motion segment comprised of asuperior vertebra 196, inferior vertebra 198, and patient-specificinterbody (PSIB) implant 200. Three views (AP 190, lateral 192, andaxial 194) are shown. PSIB 200 is shown in place with the adjacentvertebrae.

FIG. 13 shows the patient-specific interbody (PSIB) implant 216displayed in AP 210, lateral 212, and axial 214 views. The PSIB 216 isgenerated from the three-dimensional negative space created bymanipulation of the virtual vertebra into an aligned position.

In each view, several dimensions are shown including, coronal angle 218,sagittal angle 220, left lateral height 222, right lateral height 223,width 224, posterior height 226, and anterior-posterior depth 230.Structural elements or struts 232 can been seen in the AP and lateralviews 210, 212. Additionally, internal lattice 231 is shown. Lattice 231can be designed to resist compressive loads and reduce incidences ofsubsidence in patients with reduced bone density, including those withosteoporosis.

Another feature of PSIB 216 is endplate topography 234. The endplate ofthe implant can be designed to match the irregular surface of theadjacent vertebral endplate. The topography can have macro- ormicro-geometry to encourage fit, fixation, and fusion to the adjacentvertebral endplate.

In another embodiment, surfaces of the patient-specific interbodyimplant can be configured to encourage bone growth. It has been shown inclinical literature that structures having a particular pore size canencourage attachment of cells that become a precursor for boneformation. One embodiment can be configured to have the appropriate poresize to encourage bone formation.

Additionally, surfaces of the implant can be impregnated withtherapeutic agents including anti-inflammatory compounds, antibiotics,or bone proteins. The impregnation could occur as a result of exposingthe implant to solution containing the therapeutic agents, manufacturingtherapeutic agents into the substrate or surface material, coating theimplant with a therapeutic solution, among other methods. In oneembodiment, the therapeutic agents can be configured for a timed releaseto optimize effectiveness.

FIG. 14 shows a surgical kit 240 including implants 242, instrument 244,and packaging 246. Surgical kit 240 can be assembled and deliveredsterile to the operating room. In one embodiment, patient-specificinterbodies 242 can be arranged in individual wells with identifiers 248including level to implanted, external dimensions, and implant strength.Additional data 250 including patient identifier, surgeon identifier,and surgery date can be included in the data. Display of translation,rotation, manipulations to inform surgeon of amount and direction ofcorrection expected in order to reach optimal alignment.

FIG. 17 illustrates a system 352 for providing assistance formanufacturing a patient specific-implant. The system 352 can include asurgical assistance system 364 that obtains implant surgery information(e.g., digital data, images of anatomy, correction procedure data,etc.), convert the implant surgery information into a form compatiblewith an analysis procedure, apply the analysis procedure to obtainresults, and use the results to manufacture the patient-specificimplant. In some embodiments, the system 352 segments an image ofanatomy and then isolates anatomic elements in the image. Spatialrelationships between the isolated anatomic elements can be manipulatedand negative spaces between anatomic elements can be analyzed or mappedfor configuring a virtual implant. In some embodiments, the system 352can analyze one or more images of the subject to determine an virtualimplant configuration, which can include characteristics, such asparameters (e.g., dimensions), materials, angles, application features(e.g., implant sizes, implant functionality, implant placement location,graft chamber sizes, etc.), and/or aspects of applying the implant suchas insertion point, delivery path, implant position/angle, rotation,amounts of force to apply, etc.

A patient-specific implant can be manufactured based, at least in part,on the virtual implant configuration selected for the patient. Eachpatient can receive an implant that is specifically designed for theiranatomy. In some procedures, the system 352 can handle the entire designand manufacturing process. In other embodiments, a physician can alterthe implant configuration for further customization. An iterative designprocess can be employed in which the physician and system 352 worktogether. For example, the system 352 can generate a proposedpatient-specific implant. The physician can identify characteristics ofthe implant to be changed and can input potential design changes. Thesystem 352 can analyze the feedback from the physician to determine arefined patient-specific implant design and to produce apatient-specific model. This process can be repeated any number of timesuntil arriving at a suitable design. Once approved, the implant can bemanufactured based on the selected design.

The system 352 can include a surgical assistance system 364 thatanalyzes implant surgery information, for example, into arrays ofintegers or histograms, segments images of anatomy, manipulatesrelationships between anatomic elements, converts patient informationinto feature vectors, or extracts values from the pre-operative plan.The system 352 can store implant surgery information analyzed by thesurgical assistance system 364. The stored information can includereceived images of a target area, such as MRI scans of a spine, digitalimages, X-rays, patient information (e.g., sex, weight, etc.), virtualmodels of the target area, a databased of technology models (e.g., CADmodels), and/or a surgeon's pre-operative plan.

In some implementations, surgical assistance system 364 can analyzepatient data to identify or develop a corrective procedure, identifyanatomical features, etc. The anatomical features can include, withoutlimitation, vertebra, vertebral discs, bony structures, or the like. Thesurgical assistance system 364 can determine the implant configurationbased upon, for example, a corrective virtual model of the subject'sspine, risk factors, surgical information (e.g., delivery paths,delivery instruments, etc.), or combinations thereof. In someimplementations, the physician can provide the risk factors before orduring the procedure. Patient information can include, withoutlimitation, patient sex, age, bone density, health rating, or the like.

In some implementations, the surgical assistance system 364 can applyanalysis procedures by supplying implant surgery information to amachine learning model trained to select implant configurations. Forexample, a neural network model can be trained to select implantconfigurations for a spinal surgery. The neural network can be trainedwith training items each comprising a set of images (e.g., cameraimages, still images, scans, MRI scans, CT scans, X-ray images,laser-scans, etc.) and patient information, an implant configurationused in the surgery, and/or a scored surgery outcome resulting from oneor more of: surgeon feedback, patient recovery level, recovery time,results after a set number of years, etc. This neural network canreceive the converted surgery information and provide output indicatingthe pedicle screw configuration.

The assistance system 364 can generate one or more virtual models (e.g.,2D models, 3D models, CAD models, etc.) for designing and manufacturingitems. For example, the surgical assistance system 364 can build avirtual model of a surgery target area suitable for manufacturingsurgical items, including implants. The surgical assistance system 364can also generate implant manufacturing information, or data forgenerating manufacturing information, based on the computed implantconfiguration. The models can represent the patient's anatomy, implants,candidate implants, etc. The model can be used to (1) evaluate locations(e.g., map a negative 2D or 3D space), (2) select a bounding anatomicalfeature, such as a vertebral endplate, (3) create a best-fit virtualimplant, (4) define a perimeter of the anatomical feature, and/or (5)extrude a volume defined by the perimeter and perpendicular to, forexample, a best-fit plane to the interface of another anatomicalfeature. Anatomical features in the model can be manipulated accordingto a corrective procedure. Implants, instruments, and surgical plans canbe developed based on the pre or post-manipulated model. Neural networkscan be trained to generate and/or modify models, as well as other data,including manufacturing information (e.g., data, algorithms, etc.).

In another example, the surgical assistance system 364 can apply theanalysis procedure by performing a finite element analysis on agenerated three-dimensional model to assess, for example, stresses,strains, deformation characteristics (e.g., load deformationcharacteristics), fracture characteristics (e.g., fracture toughness),fatigue life, etc. The surgical assistance system 364 can generate athree-dimensional mesh to analyze the model. Machine learning techniquesto create an optimized mesh based on a dataset of vertebrae, bones,implants, tissue sites, or other devices. After performing the analysis,the results could be used to refine the selection of implants, implantcomponents, implant type, implantation site, etc.

The surgical assistance system 364 can perform a finite element analysison a generated three-dimensional model (e.g., models of the spine,vertebrae, implants, etc.) to assess stresses, strains, deformationcharacteristics (e.g., load deformation characteristics), fracturecharacteristics (e.g., fracture toughness), fatigue life, etc. Thesurgical assistance system 364 can generate a three-dimensional mesh toanalyze the model of the implant. Based on these results, theconfiguration of the implant can be varied based on one or more designcriteria (e.g., maximum allowable stresses, fatigue life, etc.).Multiple models can be produced and analyzed to compare different typesof implants, which can aid in the selection of a particular implantconfiguration.

The surgical assistance system 364 can incorporate results from theanalysis procedure in suggestions. For example, the results can be usedto suggest a surgical plan (e.g., a PLIF plan, a TLIF plan, a LLIF plan,a ALIF plan, etc.), select and configure an implant for a procedure,annotate an image with suggested insertions points and angles, generatea virtual reality or augmented reality representation (including thesuggested implant configurations), provide warnings or other feedback tosurgeons during a procedure, automatically order the necessary implants,generate surgical technique information (e.g., insertion forces/torques,imaging techniques, delivery instrument information, or the like), etc.The suggestions can be specific to implants. In some procedures, thesurgical assistance system 364 can also be configured to providesuggestions for conventional implants. In other procedures, the surgicalassistance system 364 can be programmed to provide suggestions forpatient-specific or customized implants. The suggestion for theconventional implants may be significantly different from suggestionsfor patient-specific or customized implants.

The system 352 can simulate procedures using a virtual reality system ormodeling system. One or more design parameters (e.g., dimensions,implant configuration, instrument, guides, etc.) can be adjusted based,at least in part, on the simulation. Further simulations (e.g.,simulations of different corrective procedures) can be performed forfurther refining implants. In some embodiments, design changes are madeinteractively with the simulation and the simulated behavior of thedevice based on those changes. The design changes can include materialproperties, dimensions, or the like.

The surgical assistance system 364 can improve efficiency, precision,and/or efficacy of implant surgeries by providing more optimal implantconfiguration, surgical guidance, customized surgical kits (e.g.,on-demand kits), etc. This can reduce operational risks and costsproduced by surgical complications, reduce the resources required forpreoperative planning efforts, and reduce the need for extensive implantvariety to be prepared prior to an implant surgery. The surgicalassistance system 364 provides increased precision and efficiency forpatients and surgeons.

In orthopedic surgeries, the surgical assistance system 364 can selector recommend implants, surgical techniques, patient treatment plans, orthe like. In spinal surgeries, the surgical assistance system 364 canselect interbody implants, pedicle screws, and/or surgical techniques tomake surgeons more efficient and precise, as compared to existingsurgical kits and procedures. The surgical assistance system 364 canalso improve surgical robotics/navigation systems, and provide improvedintelligence for selecting implant application parameters. For example,the surgical assistance system 364 empowers surgical robots andnavigation systems for spinal surgeries to increase procedure efficiencyand reduce surgery duration by providing information on types and sizes,along with expected insertion angles. In addition, hospitals benefitfrom reduced surgery durations and reduced costs of purchasing,shipping, and storing alternative implant options. Medical imaging andviewing technologies can integrate with the surgical assistance system364, thereby providing more intelligent and intuitive results.

The surgical assistance system 364 can include one or more input devices420 that provide input to the processor(s) 345 (e.g., CPU(s), GPU(s),HPU(s), etc.), notifying it of actions. The input devices 320 can beused to manipulate a model of the spine, as discussed in connection withFIGS. 10 and 11 . The actions can be mediated by a hardware controllerthat interprets the signals received from the input device andcommunicates the information to the processors 345 using a communicationprotocol. Input devices 320 include, for example, a mouse, a keyboard, atouchscreen, an infrared sensor, a touchpad, a wearable input device, acamera- or image-based input device, a microphone, or other user inputdevices. Processors 345 can be a single processing unit or multipleprocessing units in a device or distributed across multiple devices.Processors 345 can be coupled to other hardware devices, for example,with the use of a bus, such as a PCI bus or SCSI bus.

The system 352 can include a display 300 used to display text, models,virtual procedures, surgical plans, implants, and graphics. In someimplementations, display 330 provides graphical and textual visualfeedback to a user. In some implementations, display 330 includes theinput device as part of the display, such as when the input device is atouchscreen or is equipped with an eye direction monitoring system. Theprocessors 345 can communicate with a hardware controller for devices,such as for a display 330. In some implementations, the display isseparate from the input device. Examples of display devices are: an LCDdisplay screen, an LED display screen, a projected, holographic, oraugmented reality display (such as a heads-up display device or ahead-mounted device), and so on. Other I/O devices 340 can also becoupled to the processors 345, such as a network card, video card, audiocard, USB, firewire or other external device, camera, printer, speakers,CD-ROM drive, DVD drive, disk drive, or Blu-Ray device. Other I/O 340can also include input ports for information from directly connectedmedical equipment such as imaging apparatuses, including MRI machines,X-Ray machines, CT machines, etc. Other I/O 340 can further includeinput ports for receiving data from these types of machine from othersources, such as across a network or from previously captured data, forexample, stored in a database.

In some implementations, the system 352 also includes a communicationdevice capable of communicating wirelessly or wire-based with a networknode. The communication device can communicate with another device or aserver through a network using, for example, TCP/IP protocols. System452 can utilize the communication device to distribute operations acrossmultiple network devices, including imaging equipment, manufacturingequipment, etc.

The system 452 can include memory 350. The processors 345 can haveaccess to the memory 350, which can be in a device or distributed acrossmultiple devices. Memory 350 includes one or more of various hardwaredevices for volatile and non-volatile storage, and can include bothread-only and writable memory. For example, a memory can comprise randomaccess memory (RAM), various caches, CPU registers, read-only memory(ROM), and writable non-volatile memory, such as flash memory, harddrives, floppy disks, CDs, DVDs, magnetic storage devices, tape drives,device buffers, and so forth. A memory is not a propagating signaldivorced from underlying hardware; a memory is thus non-transitory.Memory 350 can include program memory 360 that stores programs andsoftware, such as an operating system 362, surgical assistance system364, and other application programs 366. Memory 350 can also includedata memory 370 that can include, e.g., implant information,configuration data, settings, user options or preferences, etc., whichcan be provided to the program memory 360 or any element of the system352, such as the manufacturing system 367. The system 452 can beprogrammed to perform the methods discussed in connection with FIGS. 18and 19 to manufacture implants using the manufacturing system 367.

FIG. 18 is a flow diagram illustrating a method 400 for manufacturing animplant in accordance with an embodiment of the disclosure. At block404, one or more images of anatomy are received. At block 410, featuresin images can be segmented. The features can be anatomy of interest,such as bone, organs, etc. Anatomic elements (e.g., vertebrae, vertebraldisks, etc.) can be isolated at block 420. At block 430, spatialrelationships between the isolated anatomic elements can be manipulated.Before and/or after manipulating the spatial relationships, a negativespace between anatomic elements can be mapped at block 440. At block450, at least a portion of the negative space can be filled with avirtual implant. At block 460, the virtual implant can be used toselect, design, and/or manufacture a patient-specific implant (e.g.,implant 110 of FIG. 6 ).

FIG. 19 is a flow diagram illustrating a method 500 for manufacturing animplant in accordance with an embodiment of the disclosure. At block510, a system can receive patient data and generate a patient-specificmodel based on the received patient data. At block 520, thepatient-specific model can be adjusted according to one or morecorrective procedures to produce a corrected model. The corrected modelcan be used to design a patient specific medical device. In someembodiments, the corrected model can be a 2D or 3D anatomical model ofthe patient's spine, vertebral column, etc. At block 530, dimensions ofa virtual implant/medical device can be determined using the correctedmodel. For example, the size of the virtual implant/medical device canbe determined by positioning a virtual implant/medical device at adesired location (e.g., an implantation site in the corrected model). Atblock 540, once positioned, the corrected anatomical model and/orvirtual implant can be evaluated to assess expected treatment outcomes,performance of the virtual implant (e.g., fatigue life, loadingcharacteristics, etc.), or the like. For example, contact and loadtransfer can be analyzed. The corrected model can be adjusted toproperly position anatomic elements with respect to the virtualimplant/medical device.

The patient data can include images of the patient's body, clinicianinput, treatment plan information, or the like. The corrected model canbe generated by processing (e.g., segmenting, filtering, edge detection,partitioning, etc.) the images and then analyzing, for example,anatomical features of interest. Anatomical features can be manipulated(e.g., resized, moved, translated, rotated, etc.) to generate thecorrected model. The corrected model can be used to simulate differentprocedures with different virtual implants. At block 550,patient-specific implants (e.g., implant 110 of FIG. 6 ) can be producedbased on the virtual implants, models, simulations, etc.

The methods (e.g., methods 400 and 500) can include other stepsdisclosed herein. Some implementations can be operational with numerousother computing system environments or configurations. Examples ofcomputing systems, environments, and/or configurations that may besuitable for use with the technology include, but are not limited to,personal computers, server computers, handheld or laptop devices,cellular telephones, wearable electronics, tablet devices,multiprocessor systems, microprocessor-based systems, programmableconsumer electronics, network PCs, minicomputers, mainframe computers,distributed computing environments that include any of the above systemsor devices, or the like.

The embodiments, features, systems, devices, materials, methods andtechniques described herein may, in some embodiments, be similar to anyone or more of the embodiments, features, systems, devices, materials,methods and techniques described in the following:

-   -   U.S. application Ser. No. 16/048,167, filed on Jul. 27, 2017,        titled “SYSTEMS AND METHODS FOR ASSISTING AND AUGMENTING        SURGICAL PROCEDURES;”    -   U.S. application Ser. No. 16/242,877, filed on Jan. 8, 2019,        titled “SYSTEMS AND METHODS OF ASSISTING A SURGEON WITH SCREW        PLACEMENT DURING SPINAL SURGERY;”    -   U.S. application Ser. No. 16/207,116, filed on Dec. 1, 2018,        titled “SYSTEMS AND METHODS FOR MULTI-PLANAR ORTHOPEDIC        ALIGNMENT;”    -   U.S. application Ser. No. 16/383,215, filed on Apr. 12, 2019,        titled “SYSTEMS AND METHODS FOR ORTHOPEDIC IMPLANT FIXATION;”        and    -   U.S. Application No. 62/773,127, filed on Nov. 29, 2018, titled        “SYSTEMS AND METHODS FOR ORTHOPEDIC IMPLANTS.”

All of the above-identified patents and applications are incorporated byreference in their entireties. In addition, the embodiments, features,systems, devices, materials, methods and techniques described hereinmay, in certain embodiments, be applied to or used in connection withany one or more of the embodiments, features, systems, devices, or othermatter.

The ranges disclosed herein also encompass any and all overlap,sub-ranges, and combinations thereof. Language such as “up to,” “atleast,” “greater than,” “less than,” “between,” and the like includesthe number recited. Numbers preceded by a term such as “approximately”,“about”, and “substantially” as used herein include the recited numbers(e.g., about 10%=10%), and also represent an amount close to the statedamount that still performs a desired function or achieves a desiredresult. For example, the terms “approximately”, “about”, and“substantially” may refer to an amount that is within less than 10% of,within less than 5% of, within less than 1% of, within less than 0.1%of, and within less than 0.01% of the stated amount.

While embodiments have been shown and described, various modificationsmay be made without departing from the scope of the inventive conceptsdisclosed herein.

What is claimed is:
 1. A system for designing an orthopedic implant, the system comprising: one or more processors; and one or more memories storing instructions that, when executed by the one or more processors, cause the system to perform a process comprising: segmenting anatomy of interest in at least one image of anatomy; isolating separate anatomic elements of the anatomy of interest; manipulating spatial relationships between the isolated anatomic elements; after manipulating the spatial relationships, mapping a negative space between the anatomic elements, and filling at least a portion of the negative space with a virtual implant.
 2. The system of claim 1, wherein the process further comprises: after manipulating the spatial relationships, generating one or more parameters of the virtual implant based on relative positions of the anatomic elements.
 3. The system of claim 1, wherein manipulating the spatial relationships includes positioning the isolated anatomic elements at positions corresponding to a corrective procedure.
 4. The system of claim 1, wherein the process further comprises: manufacturing the orthopedic implant according to one or more parameters of the virtual implant determined based on filling the at least the portion of the negative space with the virtual implant.
 5. The system of claim 1, wherein the at least one image includes a CT scan, an MRI scan, and/or an X-ray.
 6. The system of claim 1, wherein the segmenting step is accomplished by using a threshold filter and/or a combination of filters.
 7. The system of claim 1, wherein the isolating step is accomplished by using a volumetric grow operation.
 8. The system of claim 1, wherein the manipulating step is accomplished by translating the isolated body along an axis.
 9. The system of claim 1, wherein the manipulating step is accomplished by rotating the isolated element about an axis.
 10. The system of claim 1, wherein the manipulating step is accomplished by translating the isolated element about a curve.
 11. The system of claim 1, wherein the mapping step is accomplished by selecting a first bounding anatomical feature, selecting at least a second bounding anatomical feature, and calculating a volume between the first and second bounding anatomical features.
 12. The system of claim 1, further comprising manufacturing the orthopedic implant by 3D printing, additive manufacturing, and/or subtractive manufacturing.
 13. The system of claim 1, wherein the process further comprises: creating a 3D model of the virtual implant based on the filling of the negative space with the virtual implant; converting the 3D model into 3D fabrication data; and manufacturing at least a portion of the orthopedic implant based on the 3D fabrication data.
 14. The system of claim 1, wherein the process further comprises generating a virtual three-dimensional model of the anatomy of interest with the negative space.
 15. The system of claim 1, wherein the process further comprises filling the at least the portion of the negative space with the virtual implant is performed using the negative space of the virtual three-dimensional model.
 16. The system of claim 1, wherein the negative space is a three-dimensional negative space between the anatomic elements represented by virtual three-dimensional anatomic elements.
 17. The system of claim 1, wherein the process further comprises manipulating the spatial relationships between the isolated anatomic elements by moving the anatomic elements to provide a corrective virtual model with the negative space.
 18. The system of claim 1, wherein the process further comprises generating a virtual three-dimensional corrective model of the subject's spine with the negative space.
 19. The system of claim 1, wherein filling the at least the portion of the negative space with the virtual implant is performed using the negative space of a virtual three-dimensional corrective model, wherein the virtual implant is a spine implant.
 20. The system of claim 18, wherein the negative space is a three-dimensional negative space between the anatomic elements represented by virtual three-dimensional anatomic elements.
 21. A computer-readable storage medium storing instructions that, when executed by a computing system, cause the computing system to perform operations comprising: segmenting anatomy of interest in at least one image of anatomy; isolating separate anatomic elements of the anatomy of interest; manipulating spatial relationships between the isolated anatomic elements; after manipulating the spatial relationships, mapping a negative space between the anatomic elements, and filling at least a portion of the negative space with a virtual implant.
 22. The computer-readable storage medium of claim 21, wherein the operations further include generating one or more parameters based on relative positions of the anatomical elements.
 23. The computer-readable storage medium of claim 22, wherein the operations further include positioning the virtual implant between the anatomical elements prior to generating the one or more parameters.
 24. The computer-readable storage medium of claim 23, wherein the operations further include manufacturing an implant according to the one or more parameters.
 25. The computer-readable storage medium of claim 21, wherein the operations further include receiving the at least one image of anatomy from an imaging apparatus. 